1 files changed, 147 insertions, 0 deletions
diff --git a/src/pcm_export.h b/src/pcm_export.h
new file mode 100644
index 000000000..a7e7c3f68
--- /dev/null
+++ b/src/pcm_export.h
@@ -0,0 +1,147 @@
+/*
+ * Copyright (C) 2003-2012 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef PCM_EXPORT_H
+#define PCM_EXPORT_H
+
+#include "check.h"
+#include "pcm_buffer.h"
+#include "audio_format.h"
+
+#include <stdbool.h>
+
+struct audio_format;
+
+/**
+ * An object that handles export of PCM samples to some instance
+ * outside of MPD.  It has a few more options to tweak the binary
+ * representation which are not supported by the pcm_convert library.
+ */
+struct pcm_export_state {
+	/**
+	 * The buffer is used to convert DSD samples to the
+	 * DSD-over-USB format.
+	 *
+	 * @see #dsd_usb
+	 */
+	struct pcm_buffer dsd_buffer;
+
+	/**
+	 * The buffer is used to pack samples, removing padding.
+	 *
+	 * @see #pack24
+	 */
+	struct pcm_buffer pack_buffer;
+
+	/**
+	 * The buffer is used to reverse the byte order.
+	 *
+	 * @see #reverse_endian
+	 */
+	struct pcm_buffer reverse_buffer;
+
+	/**
+	 * The number of channels.
+	 */
+	uint8_t channels;
+
+	/**
+	 * Convert DSD to DSD-over-USB?  Input format must be
+	 * SAMPLE_FORMAT_DSD and output format must be
+	 * SAMPLE_FORMAT_S24_P32.
+	 */
+	bool dsd_usb;
+
+	/**
+	 * Convert (padded) 24 bit samples to 32 bit by shifting 8
+	 * bits to the left?
+	 */
+	bool shift8;
+
+	/**
+	 * Pack 24 bit samples?
+	 */
+	bool pack24;
+
+	/**
+	 * Export the samples in reverse byte order?  A non-zero value
+	 * means the option is enabled and represents the size of each
+	 * sample (2 or bigger).
+	 */
+	uint8_t reverse_endian;
+};
+
+/**
+ * Initialize a #pcm_export_state object.
+ */
+void
+pcm_export_init(struct pcm_export_state *state);
+
+/**
+ * Deinitialize a #pcm_export_state object and free allocated memory.
+ */
+void
+pcm_export_deinit(struct pcm_export_state *state);
+
+/**
+ * Open the #pcm_export_state object.
+ *
+ * There is no "close" method.  This function may be called multiple
+ * times to reuse the object, until pcm_export_deinit() is called.
+ *
+ * This function cannot fail.
+ *
+ * @param channels the number of channels; ignored unless dsd_usb is set
+ */
+void
+pcm_export_open(struct pcm_export_state *state,
+		enum sample_format sample_format, unsigned channels,
+		bool dsd_usb, bool shift8, bool pack, bool reverse_endian);
+
+/**
+ * Calculate the size of one output frame.
+ */
+G_GNUC_PURE
+size_t
+pcm_export_frame_size(const struct pcm_export_state *state,
+		      const struct audio_format *audio_format);
+
+/**
+ * Export a PCM buffer.
+ *
+ * @param state an initialized and open pcm_export_state object
+ * @param src the source PCM buffer
+ * @param src_size the size of #src in bytes
+ * @param dest_size_r returns the number of bytes of the destination buffer
+ * @return the destination buffer (may be a pointer to the source buffer)
+ */
+const void *
+pcm_export(struct pcm_export_state *state, const void *src, size_t src_size,
+	   size_t *dest_size_r);
+
+/**
+ * Converts the number of consumed bytes from the pcm_export()
+ * destination buffer to the according number of bytes from the
+ * pcm_export() source buffer.
+ */
+G_GNUC_PURE
+size_t
+pcm_export_source_size(const struct pcm_export_state *state, size_t dest_size);
+
+#endif